Rapid detection and differentiation method of VanA, VanB and VanC phenotypes in vancomycin-resistant enterococci

We developed a simple method that can replace the polymerase chain reaction (PCR) to distinguish between vancomycin-resistant enterococci (VRE) with the vanA, vanB and vanC genes. The method is based on induction of teicoplanin resistance by vancomycin in vanB-VRE, while the two compounds have a synergistic effect in vanC-VRE. In addition, vanA-VRE shows resistance to both vancomycin and teicoplanin, and both the compounds can induce resistance to vanA-VRE. Utilising these properties, we attempted to develop a simple method to distinguish between vanA, vanB and vanC. We compared our simple method with the PCR method in 43 strains of vanA-VRE, 35 strains of vanB-VRE and 37 strains of vanC-VRE. The results were 100% consistent with that obtained by PCR. (C) 2004 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.